Positional and configurational separation of fatty acid isomers by micro reversed-phase liquid chromatography with an Ag+-containing mobile phase

Different positional and configurational fatty acids, derivatised into the phenacylesters, were analyzed by reversed-phase liquid chromatography (RPLC ) on micropacked fused-silica columns with an Ag+-containing mobile phase. The pi-complexation strength was evaluated by plotting the selectivity coef ficients (alpha Ag+) as a function of [Ag+]. The equilibrium constants (K*) were determined by means of the hyperbolic dependence of the capacity fact ors on [Ag+]. Different fat hydrolysates and margarines taken at different stages of palm oil hydrogenation were analyzed. Data obtained with micropac ked RPLC and capillary GC for the determination of the cis/trans ratio of m onoenoic acids are compared. (C) 1999 Elsevier Science B.V. All rights rese rved.